Sic ohmic contact preparation method

A silicon carbide (SiC) ohmic contact preparation method, comprising:

• selecting a SiC substrate;
• forming a graphene/SiC composite structure by epitaxially growing a graphene on a Si-face of the SiC substrate;
• depositing an Au film on the graphene of the graphene/SiC composite structure;
• forming a Ni electrode by sputtering a Ni metal on a C-face of the SiC substrate;
• forming a first transfer electrode pattern on the Au film by a first photolithography;
• etching the Au film uncovered by the first transfer electrode pattern by a wet etching;
• etching the graphene uncovered by the Au film by a plasma etching;
• forming a second transfer electrode pattern on the Au film by a second photolithography;
• etching the Au film uncovered by the second transfer electrode pattern through a wet etching;
• forming a third transfer electrode pattern on the SiC substrate and the graphene by a third photolithography;
• and
• depositing an Au material on the graphene and the SiC substrate to form an Au electrode and then annealing, so as to obtain a SiC ohmic contact.